Optical connector plug, optical connector adapter and optical connector

ABSTRACT

An optical connector adapter has a tubular sleeve having opposite open ends each for receiving a ferrule supporting an optical fiber to bring front end faces of the ferrules into contact with each other to optically connect together the optical fibers. An adapter housing supports therein the sleeve. The adapter housing has at least one elastically deformable engaging portion projecting from an outer peripheral surface portion of the adapter housing for detachable engagement directly to a mounting board or for detachable engagement to a mounting member detachably engageable with the mounting board to detachably mount the adapter housing to the mounting board.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a division of U.S. application Ser. No.10/651,517, filed Aug. 29, 2003 now U.S. Pat. No. 6,908,233, which ishereby incorporated by reference, and priority thereto for commonsubject matter is hereby claimed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical connector plug and anoptical connector adapter as well as an optical connector for holding afront end of an optical fiber and optically connecting the opticalfibers.

2. Description of the Related Art

In a related art, optical connection of optical fibers used in opticalcommunication is carried out by a method of using an optical connectorhaving an optical connector plug holding a front end of the opticalfiber and an optical connector adapter for carrying out opticalconnection of the optical fibers by fixing the optical connector plugs,or a method of welding front end faces of the optical fibers.

According to the optical connection of the optical fibers achieved by awelding process, there is a problem that attachment and detachment ofthe optical connection of the optical fibers cannot be carried out and aproblem that the welding steps are complicated, thereby restricting theuse of the optical connector.

Further, according to an optical connector of an SC type, an FC type orthe like for carrying out optical connection by using a cylindricalmember for a ferrule holding an optical fiber and having an outerdiameter of φ2.5 mm, the optical connector cannot be downsized and awide mounting area is needed in mounting the optical connector to amounting board.

Therefore, there has been proposed an MU type optical connector using acylindrical member for a ferrule holding an optical fiber and having anouter diameter of φ1.25 mm and comparatively downsized (for example,refer to nonpatent literature 1 described below).

According to the MU type optical connector, an optical connector plugand an optical connector adapter are difficult to disengage from eachother and reliability of optical connection can be promoted. However,such an MU type optical connector is generally designed to carryoutoptical connection using an optical fiber cord provided with a tensionmember and a coating further on an outer periphery of an optical fibercore line provided with a coating on an outer periphery of an opticalfiber to carry out optical connection at a panel face on an outer sideof an optical transmission apparatus. Therefore, a number of parts islarge and downsizing thereof is difficult. Therefore, a wide mountingare is needed for mounting a comparatively small-sized MU type opticalconnector at a mounting board and there poses a problem that downsizingof the mounting board per se cannot be achieved.

Further, when the optical connector of the related art is mounted to themounting board, the optical adapter is directly fixed to the mountingboard and therefore, a space for attaching and detaching the opticalconnector plug holding the optical fiber is needed on the mounting boardand there poses a problem that not only the mounting board islarge-sized but also operational efficiency is poor.

Further, there is a problem that the conventional optical connector hasa large number of parts and that integration of the optical connectorflag and the optical connector adapter of the conventional opticalconnector is difficult to achieve.

In order to resolve such a problem, there has been proposed an opticalconnector for urging to hold a ferrule holding an optical fiber to aside of a front end face thereof in an axial direction by a leaf springfixed to a mounting board to thereby bring the front end faces of theferrules into contact with each other by predetermined pressure (forexample, refer to patent literatures 1 and 2).

(patent literature 1)

JP-A-2-259708 (pages 1 through 2, FIGS. 1 through 3)

(patent literature 2)

JP-UM-A-6-73705 (page 5, FIG. 1)

(nonpatent literature 1)

Japanese Industrial Standards (JIS) C5983 F14 type connector

However, according to the above-described optical connector using theleaf spring, there poses a problem that owing to durability performanceof the leaf spring, when attachment and detachment are repeated,durability of the leaf spring is deteriorated, a deterioration inopposing connection of optical fibers, that is, a deterioration ininsertion loss is brought about and therefore, a number of times ofattachment and detachment is restricted.

Further, according to the above-described optical connector using theleaf spring, since there is no means for restricting movement of theferrule holding the front end of the optical fiber in a rotatingdirection centering on an axis thereof, an eccentric direction of thecore of the optical fiber cannot be prescribed and the inserting loss isincreased by bringing about an eccentric shift of the core.

Further, according to the above-described optical connector using theleaf spring, there poses a problem that the ferrule is liable todisengage from the leaf spring by vibration and impact and thereliability is poor.

Further, according to the above-described optical connector using theleaf spring, the front end portion of the cylindrical body for ferruleis directly inserted into a sleeve for optical connection and therefore,there poses a problem that a defect is liable to be brought about at thepolished front end face of the cylindrical member for ferrule when aninserting angle is large or by repeating attachment and detachment, theinserting loss in optical connection is liable to increase and thereliability is poor.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an optical connector whichpromotes reliability by reducing insertion loss of an optical fiber andwhich is downsized.

In order to resolve the above-described problem, according to a firstaspect of the invention, there is provided an optical connector plugcomprising a ferrule including a cylindrical member for the ferrule forholding an optical fiber and a flange member provided at a rear endportion of the cylindrical member for the ferrule, an urge springprovided on a side of a rear end portion of the flange member of theferrule, and a plug housing for holding the ferrule and the urge springdirectly at inside thereof and directly engaged with an opticalconnector adapter inserted with a front end portion of the ferrule tocarry out optical connection, wherein the plug housing is formed with aslit capable of inserting the optical fiber in a radius directionthereof at a portion of an outer periphery thereof over an axialdirection.

According to a second aspect of the invention, there is provided theoptical connector plug according to the first aspect, wherein the rearend portion of the flange member is provided with an engaging portionfor engaging with the plug housing and the plug housing includes aholding hole for holding the ferrule in a state of being urged by theurge spring to a front end side in the axial direction by engaging withthe engaging portion of the flange member and a first rotation stopperportion engaged with the flange member for restricting movement of theferrule in a rotating direction centering on an axis thereof.

According to a third aspect of the invention, there is provided theoptical connector plug according to the second aspect, wherein the firstrotation stopper portion of the plug housing is provided to be able tochange relative positions of the plug housing and the ferrule in a statein which the ferrule is pushed against the urge spring.

According to a fourth aspect of the invention, there is provided theoptical connector plug according to any one of the first through thethird aspects, wherein the flange member is engaged with the opticalconnector adapter to restrict the ferrule from moving in the rotatingdirection centering on the axis of the ferrule.

According to a fifth aspect of the invention, there is provided theoptical connector plug according to any one of the second through thefourth aspects, wherein the flange member includes an outer periphery asection of which is rectangular, and the ferrule is restricted frommoving in the rotating direction by bringing the first rotation stopperportion into contact with two faces of an outer peripheral face of theflange member on one side opposed to each other and bringing two facesof the flange member on other side into contact with the opticalconnector adapter.

According to a sixth aspect of the invention, there is provided theoptical connector plug according to any one of the first through thefourth aspects, wherein the outer peripheral face of the flange memberis provided with an urge spring engaging projection projected over thecircumferential direction for engaging with the urge spring.

According to a seventh aspect of the invention, there is provided theoptical connector plug according to any one of the first through thesixth aspects, wherein an outer diameter of the cylindrical member forthe ferrule is 1.25 mm.

According to an eighth aspect of the invention, there is provided anoptical connector including the optical connector plug according to anyone of the first through the seventh aspects.

According to a ninth aspect of the invention, there is provided anoptical connector adapter comprising a sleeve for optical connectioninserted with ferrules holding optical fibers from sides of both endsthereof for bringing end faces of the ferrules into contact with eachother to be connected optically, and an adapter housing holding thesleeve for optical connection and, optically coupling optical connectorplugs held by the ferrules, wherein an outer periphery of the adapterhousing is provided with a first mount engaging portion attachably anddetachably engaging with a mounting board or a mounting memberattachably and detachably fixed to the mounting board to project fromone face thereof.

According to a tenth aspect of the invention, there is provided theoptical connector adapter according to the ninth aspect, wherein theadapter housing comprising a housing main body provided by integralmolding to open a sleeve inserting hole inserting to hold the sleeve foroptical connection on one side of a side face thereof, and a lid memberfitted to the sleeve inserting hole of the housing main body, whereinthe lid member is integrally provided with the first mount engagingportion projected to a side of other face of the housing main body.

According to an eleventh aspect of the invention, there is provided theoptical connector adapter according to the tenth aspect, whereinengagement of the lid member by the first mount engaging portion isdisengaged by an attaching and detaching jig.

According to a twelfth aspect of the invention, there is provided theoptical connector adapter according to the eleventh aspect, wherein theattaching and detaching jig is provided with a shape of a pin and theengagement is disengaged by elastically deforming the first mountengaging portion by inserting the attaching and detaching jig betweenthe first mount engaging portion and the housing main body.

According to a thirteenth aspect of the invention, there is provided theoptical connector adapter according to the ninth aspect, wherein theadapter housing is formed by integral molding and the one face of theadapter housing is provided with a sleeve inserting hole for insertingthe sleeve for optical connection.

According to a fourteenth aspect of the invention, there is provided theoptical connector according to any one of the ninth through thethirteenth aspects, wherein an inner side of an outer edge of an openingof the sleeve inserting hole is provided with a projection of the sleevebrought into contact with an outer peripheral face of the sleeve foroptical connection for preventing detachment from the sleeve insertinghole.

According to a fifteenth aspect of the invention, there is provided theoptical connector adapter according to any one of the ninth through thefourteenth aspects, wherein the side of the other face of the adapterhousing is provided with a second mount engaging portion for engagingwith the first mount engaging portion of other one of the adapterhousing.

According to a sixteenth aspect of the invention, there is provided theoptical connector adapter according to the fifteenth aspect, wherein aplurality of pieces of the adapter housings are laminated.

According to a seventeenth aspect of the invention, there is providedthe optical connector adapter according to any one of the ninth throughthe sixteenth aspects, wherein the adapter housing is provided with asecond rotation stopper portion engaged with an outer periphery of theferrule for restricting the ferrule from moving in a rotating direction.

According to an eighteenth aspect of the invention, there is provided anoptical connector comprising the optical connector adapter according toany one of the ninth through the seventeenth aspects.

According to a nineteenth aspect of the invention, there is provided anoptical connector comprising a ferrule comprising a cylindrical memberfor the ferrule holding a front end of an optical fiber and a flangemember fitted to a rear end portion thereof and including an engagingportion on a side of a rear end portion of the flange member, an opticalconnector plug comprising an urge spring provided on the side of therear end portion of the flange member of the ferrule, and a plug housingdirectly holding the ferrule in a state of being urged to a side of afront end thereof in an axial direction by the urge spring by beingengaged with the engaging portion of the ferrule and provided with aslit capable of inserting the optical fiber in a radius directionthereof at a portion of an outer periphery thereof over the axialdirection and an optical connector adapter comprising a sleeve foroptical connection inserted with the cylindrical members for theferrules from sides of both ends thereof for bringing end faces of thecylindrical members for the ferrules into contact with each other tooptically connect, and an adapter housing holding the sleeve for opticalconnection and having a shape for optically coupling the opticalconnector plugs, wherein the plug housing and the adapter housing areformed with engaging portions for engaging the plug housing and theadapter housing with each other, an outer periphery of the adapterhousing is provided with a first mount engaging portion for attachablyand detachably engaging with a mounting board or a mounting member fixedattachably and detachably to the mounting board to project from one facethereof.

According to a twentieth aspect of the invention, there is provided theoptical connector according to the nineteenth aspect, wherein the plughousing is provided with a first rotation stopper portion engaged withthe flange member for restricting the ferrule from moving in a rotatingdirection centering on an axis thereof and the adapter housing isprovided with a second rotation stopper portion engaged with the flangemember of the optical connector plug engaged with the adapter housingfor restricting the ferrule from moving in the rotating directioncentering on the axis of the ferrule.

According to a twenty-first aspect of the invention, there is providedthe optical connector according to the twentieth aspect, wherein theflange member is provided with an outer periphery having a section in arectangular shape and the ferrule is restricted from moving in therotating direction by bringing the first rotation stopper portion intocontact with two faces on one side of an outer peripheral face of theflange member opposed to each other and bringing the second rotationstopper portion into contact with two faces on other side of the outerperipheral face of the flange member opposed to each other.

According to a twenty-second aspect of the invention, there is providedthe optical connector according to any one of the nineteenth throughtwenty-first aspects, wherein the plug housing and the adapter housingare provided with engagement restricting portions for restrictingengaging positions in the rotating direction centering on axes thereof.

According to the invention, fabrication cost can be reduced and anintegrating step can be simplified by reducing a number of parts of theoptical connector comprising the optical connector plug and the opticalconnector adapter. Further, the reliability can be promoted withoutrestricting a number of times of attachment and detachment of theoptical connector plug and the optical connector adapter and withoutdamaging a front end face of the optical fiber. Further, by providingthe mounting member attachable and detachable to and from the opticalconnector adapter at the optical connector, it is not necessary toattach and detach the optical connector adapter and the opticalconnector plug on the mounting board and the mounting board can bedownsized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a step of mounting an opticalconnector according to Embodiment 1 of the invention;

FIGS. 2A, 2B and 2C are sectional views of the optical connectoraccording to Embodiment 1;

FIGS. 3A, 3B and 3C are plane views and a sectional view of an opticalconnector plug according to Embodiment 1 of the invention;

FIG. 4 is a plane view showing a step of integrating the opticalconnector plug according to Embodiment 1 of the invention;

FIGS. 5A, 5B and 5C are a plane view and sectional views of an opticalconnector adapter according to Embodiment 1 of the invention;

FIGS. 6A and 6B are plane views of the optical connector adapteraccording to Embodiment 1 of the invention;

FIG. 7 is a perspective view showing a step of mounting to laminate theoptical connectors according to Embodiment 1 of the invention.

FIG. 8 is a perspective view showing a state of mounting to laminate theoptical connector according to Embodiment 1 of the invention;

FIGS. 9A and 9B are a plane view and a sectional view showing a state ofmounting to laminate the optical connectors according to Embodiment 1 ofthe invention;

FIG. 10 is a perspective view showing a step of mounting to laminateoptical connectors according to Embodiment 2 of the invention;

FIG. 11 is a perspective view showing a state of mounting to laminatethe optical connectors according to Embodiment 2 of the invention;

FIG. 12 is a perspective view showing a step of integrating an opticalconnector adapter according to Embodiment 3 of the invention;

FIGS. 13A and 13B are a plane view and a sectional view of the opticalconnector adapter according to Embodiment 3 of the invention;

FIG. 14 is a perspective view showing a state of connecting the opticalconnector and a plug releasing jig according to Embodiment 3 of theinvention;

FIG. 15 is a perspective view showing a step of mounting to laminate theoptical connectors according to Embodiment 3 of the invention;

FIG. 16 is a perspective view showing a state of mounting to laminatethe optical connectors and a mount releasing jig according to Embodiment3 of the invention; and

FIG. 17 is a perspective view showing a mounting step showing otherexample of a mounting member according to other embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will be explained in details based on embodiments asfollows.

Embodiment 1

FIG. 1 is a perspective view showing a step of mounting an opticalconnector according to Embodiment 1, FIG. 2A is a sectional view showinga step of connecting the optical connector, FIG. 2B is a sectional viewshowing a state of connecting the optical connector, FIG. 2C is asectional view taken along a line 2C—2C of FIG. 2B, FIGS. 3A and 3B areplane views of an optical connector plug, FIG. 3C is a sectional viewtaken along a line 3C—3C of FIG. 3A and FIG. 4 is a plane view showing astep of integrating the optical connector plug.

As illustrated, an optical connector jig 10 comprises an opticalconnector plug 20, an optical connector adapter 50 and a mounting member70.

The optical connector plug 20 is constituted by a ferrule 21 for holdingan optical fiber 1, a plug housing 23 for directly holding the ferrule21 movably in an axial direction in a predetermined range and providedwith a first rotation stopper portion 22 for restricting movement in arotating direction, and a biasing or urge spring 24 for urging theferrule 21 to a side of a front end face in the axial direction thereof.

The ferrule 21 includes a ferrule cylindrical member 25 and a flangemember 26 provided at a rear end portion of the ferrule cylindricalmember 25.

The ferrule cylindrical member 25 is provided with a cylindrical shapeand includes an optical fiber inserting hole 27 capable of inserting theoptical fiber 1 by penetrating in the axial direction at inside thereof.A rear end portion of the optical fiber inserting hole 27 is providedwith a taper portion 27 a an inner diameter of which is graduallyincreased to an opening side. By providing such a taper portion 27 a,when the optical fiber 1 is inserted into the optical fiber insertinghole 27, a front end of the optical fiber 1 can be prevented from beingchipped or broken by being brought into contact with an end face of theferrule cylindrical member 25.

Further, as a material of the ferrule cylindrical member 25, forexample, a ceramics material of zirconia or the like, a plasticmaterial, a glass material of crystallized glass, borosilicate glass,quartz or the like, a metal material of stainless steel, nickel or thelike can be pointed out. Further, an outer diameter of the ferrulecylindrical member 25 is set to 1.25 mm according to the embodiment.

The flange member 26 includes an optical fiber core line inserting hole28 communicating with the optical fiber inserting hole 27 of the ferrulecylindrical member 25 and capable of inserting an optical fiber coreline 2 having a coating at an outer periphery of the optical fiber 1. Aside of a front end portion of the optical fiber core line insertinghole 28 constitutes a fitting hole 28 a formed by an inner diameter of asize substantially equivalent to an outer diameter of the ferrulecylindrical member 25 and fixedly attached to a rear end portion of theferrule cylindrical member 25 by press-fitting or adherence.

Further, an outer periphery on a side of a front end portion of theflange member 26 includes a flange portion 29 projected in a rectangularshape over a circumferential direction. The flange portion 29 is engagedwith a first rotation stopper portion 22 of the plug housing 23 to bementioned later in details to restrict the movement of the ferrule 21 inthe rotating direction centering on an axis thereof.

Further, an inserting portion 30 capable of inserting the urge spring 24is extended on a rear die of the flange member 26. The inserting portion30 is constituted by a small diameter portion 31 an outer diameter ofwhich is comparatively small on a side of a rear end portion thereof anda large diameter portion 32 an outer diameter of which is larger thanthat of the small diameter portion 31 on a side of the flange portion29.

An outer periphery of the large diameter portion 32 of the insertingportion 30 is provided with a projection for spring 33 engaging with theurge spring 24 by being projected over a circumferential directionthereof.

Further, an outer periphery of the small diameter portion 31 of theinserting portion 30 is provided with an engaging projection 34 an outerdiameter of which is substantially equivalent to that of the largediameter portion 32 over a circumferential direction thereof and aninclined taper face 34 a is constituted by a face on a side of a rearend portion of the engaging projection 34. The taper face 34 a providedat the engaging portion 34 is for inserting the inserting portion 30 ofthe flange member 26 into an engaging hole 36 of the plug housing 23,mention later, while pushing to widen the engaging hole 36 in insertingthereinto.

Further, according to the embodiment, the flange member 26 is formed bya metal of stainless steel or the like. Further, the material and amethod of fabricating the flange member 26 are not particularly limitedthereto but, for example, the flange member 26 may integrally be moldedto a rear end portion of the ferrule cylindrical member 25 by plastic.

Further, the urge spring 24 of a compression spring or the like isprovided at an outer periphery of the inserting portion 30 of the flangemember 26. The urge spring 24 is engaged with the projection for spring33 provided at the large diameter portion 32 of the inserting portion 30to thereby temporarily prevent the urge spring 24 from being detachedfrom the ferrule 21.

Meanwhile, the plug housing 23 comprises, for example, plastic or thelike and is provided with a ferrule holding hole 35 for holding theferrule 21 and the urge spring 24 by penetrating in the axial direction.

A rear end portion of the ferrule holding hole 35 is provided with theengaging hole 36 having an inner diameter larger than the small diameterportion 31 of the flange member 26 and smaller than the engagingprojection 34.

By inserting the small diameter portion 31 of the inserting portion 30of the flange member 26 into the engaging hole 36, the ferrule 21 isheld in the plug housing 23 movably in the axial direction by apredetermined amount.

That is, when the inserting portion 30 of the flange member 26 isinserted into the engaging hole 36, the engaging projection 34 having anouter diameter larger than the engaging hole 36 pushes to widen theengaging hole 36 to elastically deform. When the engaging projection 34has passed through the engaging hole 36, the inner diameter of theengaging hole 36 recovers to the original inner diameter and theengaging projection 34 is brought into contact with the rear end face ofthe plug housing 23 at which the engaging hole 36 is opened to therebyhold the ferrule 21 to the plug housing 23 in a state in which movementthereof on a side of a front end face thereof is restricted.

Further, the urge spring 24 held at an outer peripheral face of theinserting portion 30 of the flange member 26 of the ferrule 21 urges theferrule 21 to a front end side in the axial direction of the plughousing 23 by bringing one end thereof into contact with the flangeportion 29 and bringing other end thereof into contact with an innerface thereof at which the engaging hole 36 is opened.

Further, as described above, the ferrule 21 urged to the front end sidein the axial direction by the urge spring 24 is held in the state inwhich the ferrule 21 is urged to the front end face side by restrictingthe movement to the front end side in the axial direction by bringingthe engaging projection 34 provided at the flange member 26 into contactwith the rear end face of the plug housing 23 at which the engaging hole36 is opened.

Further, since the engaging hole 36 of the plug housing 23 is pushed towiden to the engaging projection 34 when the inserting portion 30 of theflange member 26 is inserted thereinto, two intermittent openingportions 37 are provided at the rear end portion of the plug housing 23at which the engaging hole 36 is provided over a circumferentialdirection at a surrounding of the engaging hole 36. The surrounding ofthe engaging hole 36 is liable to be deformed elastically by the openingportions 37 and the inserting portion 30 of the flange member 26 isfacilitated to be inserted into the engaging hole 36.

Further, an outer peripheral face of the plug housing 23 is providedwith a slit for optical fiber 38 for communicating the ferrule holdinghole 35 to outside over the axial direction. The slit for optical fiber38 is formed by a width larger than diameters of the optical fiber 1 andthe optical fiber core line 2 held by the ferrule 21 and more or lesssmaller than the outer diameter of the small diameter portion 31 of theflange member 26.

In integrating the optical connector plug 20, the slit for optical fiber38 simplifies the integration by attaching the plug housing plug 23 tothe ferrule 21 holding the optical fiber 1 and the optical fiber coreline 2 later without previously inserting the optical fiber 1 and theoptical fiber core line 2 into the plug housing 23.

By providing the slit for optical fiber 38 to the plug housing 23 inthis way, it is not necessary to previously insert the optical fiber 1into the plug housing 23 and therefore, the yield can be promoted bypreventing the optical fiber 1 from being broken or damaged.

Further, the plug housing 23 is provided with a pair of claw portions 40to interpose the ferrule 21 and provided with locking claws 39 at innerfaces of front end portions thereof opposed to each other.

The claw portions 40 are for engaging the optical connector plug 20 andthe optical connector adapter 50 by being engaged with an adapterhousing 52 of the optical connector adapter 50 to be mentioned later indetails.

Further, regions of the respective claw portions 40 opposed to theflange portion 29 are respectively provided with the first rotationstopper portions 22 provided to project to be brought into contact withrespectives of the pair of faces of the outer peripheral face of theflange portion 29 opposed to each other.

The first rotation stopper portions 22 provided at respectives of theclaw portions 40 are brought into contact with the pair of faces of theouter peripheral face of the flange portion 29 opposed to each other,that is, by interposing the flange portion 29 by the first rotationstopper portions 22 provided at the pair of claw portions 40, movementof the ferrule 21 in the rotating direction centering on the axis isrestricted relative to the plug housing 23.

Further, the pair of claw portions 40 are formed at an interval by whichinner faces thereof opposed to each other on a side of the rear endportion of the first rotation stopper portion 22 is not brought intocontact with the flange portion 29 when the flange portion 29 isrotated.

That is, when the ferrule 21 of the optical connector plug 20 is pressedto the side of the rear end portion in the axial direction against urgeforce of the urge spring 24, engagement between the first rotationstopper portion 22 and the flange portions 29 is disengaged and theferrule 21 can be rotated relative to the plug housing 23. Thereby, evenafter integrating the ferrule 21 and the plug housing 23, positioning ofthe ferrule 21 in the rotating direction can be carried out by aneccentric direction of the optical fiber 1, and insertion loss can bereduced by matching eccentric directions of the optical connector plugs20 when the optical connector plugs 20 are opposedly connected by theoptical connector adapter 50 to be mentioned later in details.

Further, according to the embodiment, a groove portion 41 having apredetermined depth is formed at a front end face of the flange portion29 and the ferrule 21 may be pressed to the rear end portion side androtate in a pressed state by a jig engaged with the groove portion 41,although not particularly illustrated.

Further, as shown by FIG. 1, one of edge portions of one of the clawportions 40 is provided with an engagement restricting portion 42 to beengaged with an engagement restricting recess portion 63 a of theoptical connector adapter 50, mentioned later.

By providing the engagement restricting portion 42 only at one of theedge portions of one of the claw portions 40, the engagement restrictingportion 42 can restrict a position of engaging the optical connectorplug 20 to the optical connector adapter 50 in the rotating directioncentering on the axis. That is, when the optical connector plug 20 isengaged with the optical connector adapter 50, the optical connectorplug 20 and the optical connector 50 can be engaged with each otheralways at the same rotating position. Thereby, when the opticalconnector plugs 20 are opposedly connected, eccentric directions of theoptical fibers 1 are not different from each other and the insertionloss can be prevented from increasing.

As a method of integrating the optical connector plug 20, first, theferrule 21 is formed by fixing the flange member 26 to the rear endportion of the ferrule cylindrical member 25 by press-fitting. Next, byinserting the inserting portion 30 of the flange member 26 into the urgespring 24, the urge spring 24 is engaged with the projection for spring33 provided on the large diameter portion 32 and the urge spring 24 istackedly fixed or integrally mounted to the outer peripheral face of theinserting portion 30.

Next, the ferrule 21 integrally mounted or tackedly fixed with the urgespring 24 is adhered with the optical fiber 1 and the optical fiber coreline 2 via a thermosetting type adhering agent. A front end face of theferrule 21 holding the optical fiber 1 and the optical fiber core line 2in this way is polished by a polishing apparatus or the like along witha front end face of the optical fiber 1.

Thereafter, as shown by FIG. 4, the optical fiber core line 2 held bythe ferrule 21 is inserted into the slit for optical fiber 38 of theplug housing 23 and the inserting portion 30 of the flange member 26 isinserted into the engaging hole 36 of the plug housing 23. At thisoccasion, the inserting portion 30 is inserted into the engaging hole 36while pressing to widen the engaging hole 36 by the engaging projection34 and the engaging projection 34 is engaged with the engaging hole 36in the state in which movement to the front end side is restricted.

Thereby, the optical connector plug 20 according to the embodiment canbe constituted by holding the ferrule 21 movably in the axial directionby a predetermined amount in the ferrule holding hole 35 of the plughousing 23 in the state in which the ferrule 21 is urged to the frontend side in the axial direction and the movement in the rotatingdirection centering on the axis is restricted by the first rotationstopper portions 22 of the claw portions 40.

Since the optical connector plug 20 is constituted only by the ferrule21, the urge spring 24 and the plug housing 23 in this way, fabricationcost can be reduced by reducing a number of parts. Further, a procedureof integrating the optical connector plug 20 can be simplified since theurge spring 24 can tackedly be fixed to the rear end portion of theferrule 21 and the plug housing 23 can be fixed to the ferrule 21 afterfixing the optical fiber 1 to the ferrule 21.

Further, a comparison of dimensions and numbers of parts between theoptical connector plug 20 having such a constitution and the MU typeoptical connector plug (JIS C5983 F14 type optical connector) of therelated art is shown in Table 1 shown below.

TABLE 1 embodiment 1 related art total length (mm) 12.8 35 width (mm)4.5 6.6 height (mm) 3.6 4.35 number of parts 4 7

As shown by Table 1, a number of parts of the optical connector plug 20of Embodiment 1 is smaller than that of the MU type optical connectorplug of the related art and all of the total length, the width and theheight can be downsized. Thereby, downsizing of the optical connector 10using the optical connector plug 20 can be achieved and when the opticalconnector 10 is mounted to a mounting board, high density formation canbe achieved.

Further, the optical connector 10 using the optical connector plug 20optically connects the optical fiber core lines 2 provided with coatingsat outer peripheries of the optical fibers 1 above a mounting board 100and therefore, it is not necessary to use an optical fiber cableprovided with a tension member and a coating at the outer periphery ofthe optical fiber core line 2 and downsizing can be carried out alsothereby.

Next, the optical connector adapter 50 of the optical connector 10 willbe explained in details.

FIG. 5A is a plane view from a side of a bottom face of the opticalconnector adapter, FIG. 5B is a sectional view taken along a line 5B—5Bof FIG. 5A, FIG. 5C is a sectional view taken along a line 5C—5C of FIG.5A and FIGS. 6A and 6B are plane views from a side of an end face and aside of an upper face of the optical connector adapter.

As shown by FIGS. 5A, 5B and 5C, the optical connector adapter 50 isconstituted by a sleeve for optical connection 51 inserted with thefront end portion of the ferrule cylindrical member 25 and the adapterhousing 52 including the sleeve for optical connection 51.

The sleeve for optical connection 51 is provided with a cylindricalshape and includes a ferrule inserting hole 53 provided by penetratingin an axial direction thereof and a streak of slit 53 a provided fromone end side to other end side in the longitudinal direction. Further,the ferrule inserting hole 53 is formed by an inner diameter more orless smaller than an outer diameter of the cylindrical member forferrule 25.

Optical connection is carried out by respectively inserting front endportions of the cylindrical members for ferrule 25 from openings on bothsides of the ferrule inserting hole 53 of the sleeve for opticalconnection 51. At this occasion, the sleeve for optical connection 51 iselastically deformed in a direction of expanding the slit 53 a byinserting the front end portions of the cylindrical members for ferrule25 and therefore, the front end portions of the cylindrical members forferrule 25 can opposedly be connected by being brought into closecontact with the inner face of the ferrule inserting hole 53 to hold.

Furthers as a material of the sleeve for optical connection 51, forexample, a ceramic material of zirconia or the like or a metal materialof copper alloy or the like can be pointed out.

Further, the adapter housing 52 is formed by, for example, integrallymolding a resin of plastic or the like and is provided with a throughhole 54 for holding the sleeve for optical connection 51 by penetratingin the axial direction.

The cylindrical members for ferrule 25 are inserted from the both endsides of the through hole 54 to be inserted into the sleeve for opticalconnection 51 held in the through hole 54.

That is, the through hole 54 is provided with a sleeve holding portion55 having a diameter more or less larger than the outer diameter of thesleeve for optical connection 51 substantially on a central side thereofand communication holes 56 each having an inner diameter substantiallyequivalent to the outer diameter of the cylindrical member for ferrule25 on both end sides of the sleeve holding portion 55 and a steppeddifference portion 57 is provided by a difference between innerdiameters of these.

By bringing both end faces of the sleeves for optical connection 51 incontact with the stepped difference portions 57, the sleeve for opticalconnection 51 is held by the sleeve holding portion 55 in a state inwhich movement thereof in the axial direction is restricted.

Further, the adapter housing 52 is provided with a sleeve inserting hole58 formed by a size equivalent to that of the sleeve holding portion 55for communicating the sleeve holding portion 55 to outside and thesleeve for optical connection 51 is inserted into the sleeve holdingportion 55 from the sleeve inserting hole 58.

Further, inner side faces of the sleeve inserting hole 58 opposed toeach other are provided with two pairs of projections for sleeve 59 tobe opposed to each other which are provided to project such that widthsthereof are narrower than that of the sleeve holding portion 55. Theprojection for sleeve 59 is provided in a taper shape such that anamount of projection thereof is reduced to an opening side of the sleeveinserting hole 58. The sleeve for optical connection 51 inserted fromthe sleeve inserting hole 58 is inserted into the sleeve holding portion55 by pressing to widen the two pairs or projections for sleeve 59 andthe projections for sleeve 59 are brought into contact with an outerperipheral face of the inserted sleeve for optical connection 51,thereby, the sleeve for optical connection 51 is held in the sleeveholding portion 55 in a state in which movement in a radius directionthereof is restricted.

Further, as shown by FIG. 1 and FIGS. 2A and 2B, at the peripheries ofthe both end portions of the adapter housing 52, engaging recessportions 60 for engaging with the pair of claw portions 40 of theoptical connector plug 20 are provided at respective opposed facesthereof.

The engaging recess portions 60 are formed from both end faces of theadapter housing 52 such that lengths and thickness thereof aresubstantially equivalent to those of the claw portions 40 and a bottomface of the engaging recess portion 60 is provided with an engagingprojection portion 61 projected to a side of an opening face of theengaging recess portion 60. A taper face 61 a is formed at a face of theengaging projection portion 61 on a side thereof inserted with the clawportion 40. When the claw portions 40 are inserted into the engagementrecess portions 60 from sides of end faces thereof, an interval betweenthe pair of claw portions 40 is pressed to widen by elasticallydeforming the claw portions 40 by bringing the locking claws 39 intocontact with the taper faces 61 a of the engaging projection portions 61and the locking claws 39 passing the engaging projection portions 61 areengaged with the engaging projection portions 61 to thereby engage theoptical connector plug 20 and the optical connector adapter 50.

Further, both end faces of the adapter housing 52 are provided withsecond rotation stopper portions 62 for restricting movement in therotating direction of the ferrule 21 centering on the axis by beingengaged with the flange portions 29 of the flange member 26.

The second rotation stopper portions 62 are formed as a communicatinghole in a rectangular shape communicating with the communication hole 56of the through hole 54 and having a size of inserting the flangeportions 29 of the flange member 26 and notch portions 63 are formed onsides thereof of the engaging recess portions 60 inserted with theflange portions 29 of the second rotation stopper portion 62. That is,the movement in the rotating direction centering on the axis of theferrule 21 is restricted by bringing the first rotation stopper portions22 provided at the claw portions 40 into contact with ones of the outerperipheral faces of the flange portions 29 opposed to each other andbringing the second rotation stopper portions 62 into others of theouter peripheral faces of the flange portions 29 opposed to each other.

That is, the movement in the rotating direction centering on the axis ofthe ferrule 21 is restricted by engaging the optical connector plug 20and the optical connector adapter 50 by the claw portions 40 and theengaging recess portions 60.

As shown by FIG. 1 and FIGS. 6A and 6B, one of the edge portions of oneof the notch portions 63 is provided with the engagement restrictingrecess portion 63 a to be inserted with the engagement restrictingportion 42 of the optical connector plug 20.

The engaging restricting recess portion 63 a restricts an engagingposition in the rotating direction centering on the axis of the opticalconnector plug 20 by being provided at one of the edge portions of oneof the notch portions 63.

An explanation will be given here of optical connection of the opticalconnector plugs 20.

As shown by FIG. 2A, one of the optical connector plugs 20 is insertedinto one end side of the optical connector adapter 50 for engagementtherewith.

More specifically, the claw portions 40 of the optical connector plug 20are engaged with the engaging recess portions 60 of the opticalconnector adapter 50. At this occasion, the optical connector plug 20 isprovided with the engagement restricting portion 42 only at one of theedge portions of the one of the claw portions 40 and, therefore, theclaw portions 40 are engaged with the engagement recess portions 60 suchthat the engagement restricting portion 42 is inserted into theengagement restricting recess portion 63 a of the optical connectoradapter 50.

Thereby, the engaging position in the rotating direction of the opticalconnector plug 20 can be positioned relative to the optical connectoradapter 50.

Further, the ferrule 21 held between the optical connector adapter 50and the optical connector plug 20 which are engaged is held in a statein which movement in the rotating direction centering on the axis isrestricted by the first rotation stopper portions 22 and the secondrotation stopper portions 62.

The ferrule 21 is urged to be held in a state in which movement on thefront end side is restricted by bringing the engaging projection 34 ofthe inserting portion into contact with the engaging hole 36 and suchthat movement thereof to the rear end side by pressing can be carriedout.

Next, as shown by FIG. 2B, another of the optical connector plugs 20 isinserted into the other end side of the optical connector adapter 50 forengagement therewith.

Furthermore, the engagement between the optical connector adapter 50 andthe optical connector plug 20 is carried out by engaging the clawportions 40 and the engagement recess portions 60 similar to the oneoptical connector plug 20 and the optical connector adapter 50, asdescribed above.

When the other optical connector plug 20 is engaged with the opticalconnector adapter 50 in this way, by bringing the front end faces of theferrules 21 into contact with each other, the ferrules 21 are moved torear end portion sides against the urge or biasing force of the urgesprings 24.

In this way, optical connection can be carried out by bringing theferrules 21 into contact with each other in the state in which the frontend faces of the ferrules 21 urged to the front end portion sides by theurge force of the urge springs 24 are pressed by predetermined pressure.

In this way, the optical connector plug 20 and the optical connectoradapter 50 can be readily attached to each other and detached from eachother by optically connecting the optical connector plugs 20 via theoptical connector adapter 50.

Further, the movement of the ferrule 21 in the rotating direction isrestricted by the second rotation stopper portion 62 and therefore, theferrule 21 is not inserted into the sleeve for optical connection 51 ina skewed direction and the front end face of the ferrule 21 is difficultto be damaged. Thereby, not only the insertion loss in opticalconnection can be reduced but also the reliability can be promoted.

Further, in disengaging the engagement between the optical connectorplug 20 and the optical connector adapter 50, the engagement may bedisengaged by widening the claw portions 40 of the optical connectorplug 20 by a jig although not particularly illustrated.

Further, one face of the adapter housing 52 is provided with a mountengaging portion 64 for engaging with the mounting member 70.

According to the embodiment, the mount engaging portions 64 are providedas projections projected at four locations at a face of the adapterhousing 52 on the side of the sleeve inserting hole 58 and an engaginggroove 64 a is formed on the inner face side of the mount engagingportion 64.

Further, as shown by FIGS. 6A and 6B, other face of the adapter housing52 is provided with a projection for lamination 65 and an engagingportion for lamination 66 having shapes equivalent to those of aprojection for adapter 76 and an engaging portion for adapter 77 of themounting member 70 used in attachment and detachment to and from theadapter housing 52 which will be described later in details.

The projection for lamination 65 and the engaging portion for lamination66 are for laminating a plurality of the optical connectors 10 byengaging with the adapter housing of other optical connector adapterattachably and detachably thereto and therefrom although details thereofwill be described later.

Since the optical connector adapter 50 is constituted by the sleeve foroptical connection 51 and the integrally molded adapter housing 52, thecost can be reduced by reducing the number of parts.

A comparison of dimensions and numbers of parts between the opticalconnector adapter 50 constituted in this way and the MU type opticalconnector adapter (JIS C5983 F14 type optical connector) of the relatedart is shown in Table 2 shown below.

TABLE 2 embodiment 1 related art total length (mm) 13.6 26 width (mm)4.5 10.4 height (mm) 4.0 7.5 number of parts 2 5

As shown by Table 2, a number of parts of the optical connector adapter50 according to the embodiment is smaller than that of the MU typeoptical connector adapter of the related art and all of the totallength, the width and height can be downsized. Thereby, downsizing ofthe optical connector 10 using the optical connector adapter 50 can bedownsized and the high density formation can be achieved when theoptical connector 10 is mounted to a mounting board.

Next, the mounting member 70 will be described in details.

As shown by FIG. 1 and FIG. 2C, the mounting member 70 is constituted byfixing portions 71 of bent both end portions having a channel-like shapeformed by bending both end portions of a member in a shape of a flatplate and a base seat portion 72 at a region between the two mixingportions 71.

The fixing portion 71 is inserted into a fixing hole 101 provided topenetrate the mounting board 100 to hold and a front end portion thereofis constituted by a stepped difference portion 73 a width of which iswider than that of the side of the base seat portion 72 and wider thanan inner diameter of the fixing hole 101.

Further, a front end face of the fixing portion 71 is formed by a taperface 74 to facilitate to be inserted into the fixing hole 101 and anotch portion 75 notched by a predetermined amount in a longitudinalfrom the front end is provided at substantially a central portionthereof in the width direction.

When the fixing portion 71 is inserted into the fixing hole 101 of themounting board 100, the fixing portion 71 is inserted into the fixinghole 101 by bringing an edge portion of the fixing portion 71 intocontact with the taper face 74 of the fixing portion 71 and elasticallydeforming the fixing portion 71 to narrow the width of the notch portion75.

Further, the inserted fixing portion 71 is held by preventing themounting member 70 from drawing from the fixing hole 101 by bringing thestepped difference portion 73 into contact with an opening edge portionof the fixing hole 101.

Further, the base seat portion 72 of the mounting member 70 is providedwith a pair of projections for adapter 76 projected into the sleeveinserting hole 58 of the adapter housing 52 by being projected to a sideopposed to the fixing portion 71 substantially at a central portionthereof and four adapter engaging portions 77 engaged with respectivesof the engaging grooves 64 a of the four mount engaging portions 64 ofthe adapter housing 52 at edge portions in the width direction of thebase seat portion 72.

The projections for adapter 76 are provided to project to sides of bothends in the longitudinal direction of the sleeve inserting hole 58 ofthe adapter housing 52 and by bringing the projections for adapter 76into contact with the both ends in the longitudinal direction of thesleeve inserting hole 58, movement of the adapter housing 52 in theaxial direction of the optical fiber 1 is restricted relative to themounting member 70.

Further, the adapter engaging portion 77 is formed to be projected to beinclined to the width to the width direction of the base seat portion 72and by engaging the adapter engaging portion 77 to the engaging groove64 a of the mount engaging portion 64, the adapter engaging portion 77is held by restricting movement of the adapter housing 52 in the widthdirection and the attaching and detaching direction relative to themounting member 70 of the adapter housing 52.

That is, when a face of the adapter housing 52 provided with the sleeveinserting hole 58 is brought into contact with the base seat portion 72of the mounting member 70, the adapter engaging portion 77 of themounting member 70 is engaged with the mount engaging portion 64 of theadapter housing 52, the movement in the width direction and theattaching and detaching direction is restricted, the pair of projectionsfor adapter 76 provided at the base seat portion 72 are projected intothe sleeve inserting hole 58 of the adapter housing 52, thereby, theadapter housing 52 is held by restricting the movement in thelongitudinal direction.

Further, since the inner faces of the engaging grooves 64 a of the mountengaging portions 64 are formed by the inclined faces and the adapterengaging portions 77 are formed to be inclined, the mounting member 70and the optical connector adapter 50 can be attached and detached to andfrom each other by being pressed or drawn by predetermined force.

Such a mounting member 70 can be formed by, for example, metal pressing.

As a method of integrating the optical connector constituted by theoptical connector plug, the optical connector adapter and the mountingmember, first, the mounting member 70 is fixed to the mounting board100. Next, the optical connector plugs 20 are fixed to the both sides ofthe optical connector adapter 50 to thereby optically connect theoptical connector plugs 20. Thereafter, by fixing the optical connectoradapter 50 fixed with the optical connector plugs 20 to the mountingmember 70, the optical connector 10 optically connecting the opticalfibers 1 can be mounted to the mounting board 100.

Further, in order to disengage the optical connector plug of the opticalconnector mounted to the mounting board 100 in this way, the opticalconnector plug 20 may be disengaged from the optical connector adapter50 after disengaging the optical connector adapter 50 fixed with theoptical connector plugs 20 from the mounting member 70.

By making the mounting member attachable and detachable to and from theoptical connector adapter 50, the optical connector adapter 50 can beattached and detached thereto and therefrom after fixing the mountingmember 70 to the mounting board 100 and therefore, it is not necessaryto engage the optical connector adapter 50 and the optical connectorplug 20 on the mounting board 100 and it is not necessary to provide aspace for attaching and detaching the optical connector adapter 50 toand from the optical connector plug 20 at the mounting board 100.Thereby, not only the mounting board 100 can be downsized but alsomounting of the optical connector 10 can easily be carried out.

Here, FIG. 7 is a perspective view showing a step of mounting tolaminate optical connectors, FIG. 8 is a perspective view showing astate of mounting to laminate optical connectors and FIGS. 9A and 9B area plane view showing a state of mounting to laminate optical connectorsand a sectional view taken along a line 9B—9B thereof.

The projection for lamination 65 and the engaging portion for lamination66 are provided at a face of the adapter housing 52 of the opticalconnector adapter 50 on a side opposed to the mount engaging portion 64.

As shown by FIGS. 5A, 5B and 5C and FIGS. 6A and 6B, the projection forlamination 65 is provided with a shape equivalent to that of theprojection for adapter 76 of the mounting member 70 and projected intothe sleeve inserting hole 58 of other of the optical connector adapter50 to thereby prevent the other optical connector adapter 50 from movingin the longitudinal direction relative to the optical connector adapter50.

Further, the engaging portion for lamination 66 is formed to project byforming the groove along an outer peripheral edge portion to be engagedwith the mount engaging portion 64 of the other optical connectoradapter 50. By engaging the engaging portion for lamination 66 with themount engaging portion 64 of the other optical connector adapter 50, theother optical connector adapter is held attachably and detachably to andfrom the optical connector adapter 50.

By providing the projection for lamination 65 and the engaging portionfor lamination 66 for engaging with the optical connector adapter 50 atthe face of the optical connector adapter 50 on the side opposed to themount engaging portion 64 in this way, a plurality of the opticalconnector adapters 50 can be laminated, it is not necessary to align aplurality of the optical connectors 10 on the mounting board 100 in theface direction and downsizing can be achieved by narrowing the mountingarea of the mounting board 100.

Here, a comparison of the total lengths and mounting densities of theoptical connector 10 according to Embodiment 1 and the MU type opticalconnector plug (JIS C5983 F14 type optical connector) of the related artis shown in Table 3, shown below. Further, the mounting density shown inTable 3, shown below, is constituted by fixing the optical connectorplugs 20 on the both sides of the optical connector adapter and is arelative value by constituting a reference by the MU type opticalconnector of the related art.

TABLE 3 related art embodiment 1 (nonpatent literature 1) total length ⅓1 mounting density 2 or more 1 (width direction) mounting density 2 1(height direction)

As shown by Table 3, according to the optical connector 10 of theembodiment, the mounting density twice or more as much as that of the MUtype optical connector plug of the related art in the width directionand the mounting density twice as much as that of the MU type opticalconnector plug of the related art in the height direction can berealized. Further, since the total length of the optical connector 10 ofthe embodiment can be made ⅓ of that of the MU type optical connector ofrelated art, also the mounting density in the longitudinal direction ofthe embodiment can be three times as much as that of the MU type opticalconnector of the related art. Further, in the longitudinal direction,engagement and disengagement of the optical connector plug 20 and theoptical-connector adapter 50 can be carried out by a narrow area andtherefore, a substantial mounting density of the embodiment can be madethree times as much as that of the MU type optical connector of therelated art.

Embodiment 2

FIG. 10 is a perspective view showing a step of mounting to laminateoptical connectors according to Embodiment 2 and FIG. 11 is aperspective showing a state of mounting to laminate optical connectersaccording to Embodiment 2. Further, members similar to those ofEmbodiment 1, mentioned above, are attached with the same notations andduplicated explanation thereof will be omitted.

As shown by FIG. 10 and FIG. 11, an optical connector 10A is providedwith the optical connector plug 20, an optical connector adapter 50A anda mounting member 70A.

The mounting member 70A comprises the bent portion 71 and a base seatportion 72A and adapter engaging portions 77A are provided at edgeportions on both sides in a width direction of the base seat portion72A.

The adapter engaging portions 77A are formed to bend to project to aside opposed to the bent portion 71 and formed such that front endportions thereof are bent to both sides in the width direction toconstitute directions the same as directions of the face of the baseseat portion 72A.

An adapter housing 52A of the optical connector adapter 50A engaged withthe mounting member 70A is provided with a mount engaging portion 64Aprojected to a side of the sleeve inserting hole 58.

The mount engaging portion 64A is provided to project to the side of themounting member 70A and a front end portion thereof is formed in a shapeprojected to an inner side.

The optical connector adapter 50A and the mounting member 70A can engagethe mount engaging portion 64A and the adapter engaging portion 77A bysliding to move in a state in which a face of the adapter housing 52A onthe side of the sleeve inserting hole 58 is brought into contact withthe base seat portion 72A of the mounting member 70A.

Further, a face of the mount engaging portion 64A of the adapter housing52A on a side opposed to the mount engaging portion 64A is provided witha lamination engaging portion 66A in a groove-like shape to be engagedwith the mount engaging portion 64A of other of the optical connectoradapter 50A.

The optical connectors 10A can be mounted to laminate on the mountingboard 100 by attachably and detachably laminating a plurality of theoptical connector adapters 50A by the lamination engaging portions 66A.

In this way, according to the embodiment, the optical connector adapter50A is moved to slide to engage with the mounting member 70A to therebymake the optical connector adapter 50A and the mounting member 70Aattachable and detachable to and from each other and thereby, similar toEmbodiment 1, mentioned above, attachment and detachment of the opticalconnector adapter 50A to and from the optical connector plug 20A can befacilitated to execute and the mounting board 100 can be downsized.

Embodiment 3

FIG. 12 is a perspective view showing a step of integrating an opticalconnector adapter according to Embodiment 3 and FIGS. 13A and 13B are aplane view of the optical connector adapter and a sectional view takenalong a line 13B—13B thereof. Further, members similar to those ofEmbodiments 1 and 2, mentioned above, are attached with the samenotations and a duplicated explanation thereof will be omitted.

As shown by FIG. 12 and FIGS. 13A and 13B, an optical connector adapter50B of the embodiment is provided with the sleeve for optical connection51 inserted with a front end portion of a cylindrical member for ferruleand an adapter housing 52B including the sleeve for optical connection51 and an adapter housing 52B and is constituted by a housing main body110 provided with a sleeve inserting hole 58B inserted with the sleevefor optical connection 51 and opened at one face thereof and a lidmember 120 fitted to the sleeve inserting hole 58B of the housing mainbody 110.

The housing main body 110 is formed by, for example, integrally moldinga resin of plastic or the like and is provided with the through hole 54penetrated in the axial direction similar to Embodiment 1, as describedabove.

The through hole 54 includes a sleeve holding portion (not illustrated)holding the sleeve for optical connection 51 substantially on thecentral side and the through holes 56 inserted with the cylindricalmembers for ferrule on sides of both ends of the sleeve holding portionand a stepped difference portion (not illustrated) is provided by adifference between inner diameters of the sleeve holding portion and thethrough hole 56.

Further, the housing main body 110 is provided with the sleeve insertinghole 58B formed by a size substantially equivalent to the sleeve holdinghole for communicating the sleeve holding hole and outside at the oneface. A portion of an opening side of the sleeve inserting hole 58Bconstitutes a fitting portion 111 larger than the sleeve holding portionsuch that the lid member 120 is fitted thereto and the fitted lid member120 is not inserted up to the sleeve holding portion and there isprovided a stepped difference portion for lid 112 brought into contactwith the lid member 120 by the fitting portion 111 forrestricting-movement of the sleeve holding portion of the lid member 120to the sleeve holding portion.

Further, a pair of fixing recess portions 113 for engaging with fixingprojections 122 of the lid member 120 at side faces thereof opposed toeach other are provided at inner faces of the fitting portions 111 ofthe housing member 110.

Further, two side faces of the housing main body 110 are provided withrecess portions for insertion 114 into which mount engaging portions 64Bof the lid member 120 are inserted to guide when the lid member 120 isfitted to the fitting portion 111 which will be described later indetails.

Further, the housing main body 110 is provided with a plug releasinginsertion hole 115 to be inserted with a plug releasing jig, decribedlater in more detail, at a region in correspondence with the lockingclaw 39 of the claw portion 40 of the optical connector plug 20 when thehousing main body 110 is engaged with the optical connector plug 20 ofEmbodiment 1, as described above.

The plug releasing insertion hole 115 is opened to the steppeddifference portion for lid 112 provided by the fitting portion 111 andis not closed when the lid member 120 is fitted to the fitting portion111.

Meanwhile, the lid member 120 is formed by, for example, integrallymolding a resin of plastic or the like similar to the housing main body110 and is constituted by a lid portion 121 fitted to the fittingportion 111 and brought into contact with the stepped difference portionfor lid 112 and is constituted by the mount engaging portion 64Bprojected from a side of the face opposed to a face provided with thefitting portion 111 of the housing main body 110.

The lid portion 121 is provided with fixing projection portions 122respectively projected into the pair of fixing recess portions 113 whenthe lid portion 121 is fitted to the fitting portion 111 of the housingmain body 110.

Further, the lid portion 121 is provided with a projection forlamination 65B engaged with the mount engaging portion 64B of other ofthe optical connector adapter 50B.

The lid portion 121 is provided to project with the pair of mountengaging portions 64B integrally formed therewith from a bottom faceside. The mount engaging portion 64B is provided to project by apredetermined amount from a face opposed to a face of the housing mainbody 110 provided with the fitting portion 111 by being inserted intothe insertion recess portion 114 of the housing main body 110 when thelid member 120 is fitted to the fitting portion 111 of the housing mainbody 110.

At inner faces of front end portions of the pair of mount engagingportions 64B opposed to each other, there are provided mount engagingprojections 113 to be engaged with a mounting member or other of theadapter holding 52B.

Further, the lid portion 121 is provided with jig inserting holes 124for inserting a mount engagement releasing jig having a shape of a pinfor releasing engagement between the mount engaging portion 64B and themounting member or other of the adapter housing 52B, described later indetails in correspondence with respectives of the pair of mount engagingportions 64B.

The jig inserting hole 124 is arranged on the inner face side of each ofthe mount engaging portions 64B and the inner face of the mount engagingportion 64B is provided with a recess portion for inserting jig 125 tobe inserted with mount engagement releasing jig continuous to theinserting hole 123.

A taper face 125 a is constituted on a side of a front end portion ofthe mount engaging portion 64B of the jig inserting recess portion 125of the mount engaging portion 64B and when the mount engagementreleasing jig is inserted into the jig inserting hole 124 of the lidmember 120, a front end of the mount engagement releasing jig is broughtinto contact with the taper face 125 a of the jig insertion recessportion 125, the taper face 125 a is pushed to widen by pushing themount engagement releasing jig further and the mount engaging portions64B are elastically deformed in directions remote from each other.

Further, the recess portion for insertion 114 of the housing main body110 to be fitted with the lid member 120 is provided with a jig guidingrecess portion 115 to be inserted with a front end of the mountengagement releasing jig inserted into the jig inserting hole 124 andthe mount engagement releasing jig is guided by the jig guiding recessportion 115.

According to the optical connector adapter 50B having such aconstitution, since the mount engaging portion 64B provided at the lidmember 120 fitted with one face of the housing main body 110 is providedto project from other face of the housing member 110, the mount engagingportion 64B can be prolonged to facilitate elastic deformation.Therefore, the mount engaging portion 64B can be prevented from beingcracked or broken in engaging and disengaging the optical connectoradapter 50B to and from the mounting member or other of the opticalconnector adapter 50B by the mount engaging portion 64.

Here, the optical connector 10B using the optical connector adapter 50Bwill be explained. Further, FIG. 14 is a perspective view showing astate of connecting the optical connector according to Embodiment 3 andthe plug releasing jig.

Here, the optical connector plug 20 used in the optical connector 10Balong with the optical connector adapter 50B of the embodiment issimilar to that of Embodiment 1, mentioned above, and therefore, aduplicated explanation thereof will be omitted.

As shown by FIG. 14, the optical connector plug 20 and the opticalconnector adapter 50B of the optical connector 10B are engaged with eachother similar to Embodiment 1 described above.

Further, the engagement is released by the adapter releasing jig 200.

Here, the adapter releasing jig 200 is provided with releasing portions201 comprising a shape of a pair of flat plates inserted into the plugreleasing inserting holes 115 of the adapter housing 52B at a front endthereof and a front end of the releasing portion 201 constitutes a taperportion 202 a thickness of which is gradually reduced.

When the releasing portions 201 having the taper portions 202 areinserted into the plug releasing inserting holes 115, the releasingportions 201 are interposed between the locking claws 39 and the adapterhousing 52B while pushing to widen to elastically deform the clawportions 40 of the optical connector plug 20 to thereby releaseengagement between the optical connector plug 20 and the opticalconnector adapter 50B.

Further, an explanation will be given of mounting the optical connector10B to a mounting board.

FIG. 15 is a perspective view showing a step of mounting to laminate theoptical connector according to Embodiment 3 and FIG. 16 is a perspectiveview showing a state of mounting to laminate the optical connectoraccording to Embodiment 3 and the mounting releasing jig. Further,members similar to those of Embodiments 1 and 2, mentioned above, areattached with the same notations and a duplicated explanation thereofwill be omitted.

As shown by FIG. 15, a mounting member 70B to be mounted on the mountingboard 100 is constituted by fixing portions 71 at the two bent endportions and a base seat portion 72B at a region between the two fixingportions 71.

The base seat portion 72B is provided with an adapter engaging portion77B with which the mount engaging portion 64B of the optical connectoradapter 50B is engaged and projections for adapter 76B on both sides ofthe adapter engaging portion 77B.

By bringing the projections for adapter 76B into contact with the mountengaging portions 64B engaged with the adapter engaging portion 77B, theoptical connector 10B is restricted from moving in the axial directionof the optical fiber 1 relative to the mounting member 70B.

The optical connector 10B is fixed attachably and detachably to and fromthe mounting member 70B via the mount engaging portions 64B.

Further, other of the optical connector 10B is laminated on the opticalconnector 10B fixed to the mounting member 70B via the mount engagingportions 64B.

In details, the optical connector 10B is laminated with other of theoptical connector 10B by engaging the mount engaging portions 64B of theother optical connector 10B with the projections for lamination 65Bprovided at the lid member 120 of the optical connector 10B on themounting member 70B.

Further, engagement of the laminated optical connectors 10B andengagement of the optical connector 10B with the mounting member 70B canbe released by the mount releasing jig 210 shown in FIG. 16.

The mount releasing jig 210 is provided with the pair of releasingportions 211 each having a shape of a pin inserted into the jiginserting holes 114 of the adapter housing 52B at a front end thereof.

When the releasing portions 211 of the mount releasing jig 210 areinserted into the jig inserting holes 124, as described above, the frontends of the releasing portions 210 push to open to elastically deformthe mount engaging portions 64B and engagement of the optical connectors10B or the optical connector 10B and the mounting member 70B isreleased.

In this way, the optical connector 10B of the embodiment can bedownsized by reducing a number of parts and since the number of parts isreduced, releasing of the engagement between the optical connector plug20 and the optical connector adapter 50B as well as releasing ofengagement between the optical connectors 10B or between the opticalconnector 10B and the mounting member 70B can easily be carried out byusing the adapter releasing jig 200 or the mount releasing jig 210.Further, according to the optical connector 10B mounted to the mountingboard 100, releasing of engagement between the optical connector plug 20and the optical connector adapter 50B as well as releasing of engagementbetween the optical connectors 10B or the optical connector 10B and themounting member 70B are not carried out so frequently and therefore, thereleasing is not troublesome even by the adapter releasing jig 200 orthe mount releasing jig 210.

Although the invention has been explained by Embodiments 1 through 3 asdescribed above, the optical connector of the invention is not limitedto the above-described.

For example, according to Embodiments 1 through 3, mentioned above, theshape of the flange portion 29 and the shapes of the first rotationstopper portion 22 and the second rotation stopper portion 62 forrestricting movement of the ferrule 21 in the rotating directioncentering on the axis are not limited to those of Embodiments 1 through3, mentioned above, for example, there may be constructed a constitutionin which the flange portion is formed in a shape of a circular disk andprovided with key grooves over the axial direction at four locationsuniformly over the circumferential direction and the first rotationstopper portion and the second rotation stopper portion may beconstituted by projections projected into the key grooves.

Moreover, so far as movement of the ferrule in the rotating directioncan be restricted by the optical connector plug and the opticalconnector adapter, an effect similar to those of Embodiments 1 through3, as described above, can be achieved.

Further, although according to Embodiments 1 through 3, mentioned above,the mounting members 70 through 70B are provided with the bent portions71 for engaging with the fixing holes 101 of the mounting board 100 andthe mounting members 70, 70A through 70B are mounted on the mountingboard 100, a method of mounting the mounting members 70, 70A through 70Bon the mounting board 100 is not particularly limited thereto.

Here, other example of a mounting member is shown in FIG. 17. Further,FIG. 17 is a perspective view showing a mounting step showing a modifiedexample of the mounting member of Embodiment 1.

As shown by FIG. 17, a mounting member 70C is not provided with a bentportion and is constituted only by a base sheet portion 72C.

Fixing projections 72A projected in a face direction are provided onsides of both ends in the longitudinal direction of the base seatportion 72C and sides of bottom faces of the fixing projections 72 a arebonded onto the mounting board 100.

Further, bonding of the fixing projection 72 a and the mounting board100 is not particularly limited but, for example, bonding can be carriedout by adhesion via an adhering agent, brazing or soldering.

Also the mounting member 70C can be formed by metal pressing.

Further, although according to Embodiments 1 through 3, mentioned above,the optical connectors 10 through 10B are fixed attachably anddetachably to and from the mounting board 100 via the mounting members70 through 70B fixed thereto attachably and detachably, Embodiments 1through 3 are not particularly limited thereto but, for example, in thecase of the optical connector 10B having the mount engaging portions 64Baccording to Embodiment 3, the optical connector 10B may directly befixed onto the mounting board 100. Even by such a constitution, theoptical connector 10B can be fixed attachably and detachably to and fromthe mounting board 100 and cost can be reduced and downsizing can beachieved by reducing the number of parts of the optical connector,particularly, the number of parts of the optical connector adapter.

As has been explained above, according to the invention, respectives ofthe optical connector plug, the optical connector adapter and themounting member are constituted by reducing the numbers of parts andtherefore, the integrating step can be simplified and downsizing can beachieved by reducing the fabrication cost. Further, the reliability canbe promoted without damaging the front end or the like of the opticalfiber in attachment and detachment without restricting the number oftimes of attachment and detachment of the optical connector adapter andthe optical connector plug. Further, since the optical connector adapterand the mounting member mounted to the mounting board are made to beattachable and detachable to and from each other and therefore, it isnot necessary to carry out attachment and detachment of the opticalconnector adapter and the optical connector plug on the mounting boardand downsizing of the mounting board can be achieved.

1. An optical connector adapter comprising: a tubular sleeve havingopposite open ends each for receiving a ferrule supporting an opticalfiber to bring front end faces of the ferrules into contact with eachother to optically connect together the optical fibers; and an adapterhousing supporting therein the sleeve, the adapter housing having atleast one elastically deformable engaging portion projecting from anouter peripheral surface portion of the adapter housing for detachableengagement directly to a mounting board or for detachable engagement toa mounting member detachably engageable with the mounting board todetachably mount the adapter housing to the mounting board.
 2. Anoptical connector adapter according to claim 1; wherein the adapterhousing comprises a main body having an insertion hole at a first mainsurface thereof for receiving therethrough the tubular sleeve, and a lidmember for covering the insertion hole, the lid member having theelastically deformable engaging portion which projects from a secondmain surface of the main body opposite the first main surface when thelid member covers the insertion hole.
 3. An optical connector adapteraccording to claim 2; wherein the main body of the adapter housingcomprises an integrally molded structure.
 4. An optical connectoradapter according to claim 1; wherein the adapter housing has aninsertion hole for receiving therein the sleeve.
 5. An optical connectoradapter according to claim 4; wherein the adapter housing has aprojection disposed at an outer edge of an opening of the insertion holefor contacting an outer peripheral surface of the sleeve to preventremoval of the sleeve from the insertion hole.
 6. An optical connectoradapter according to claim 1; wherein the at least one elasticallydeformable engaging portion comprises a pair of elastically deformableengaging portions projecting from the outer peripheral surface portionof the adapter housing for detachable engagement directly to themounting board or for detachable engagement to the mounting memberdetachably engageable with the mounting board to detachably mount theadapter housing to the mounting board.
 7. An optical connector adapteraccording to claim 6; wherein the adapter housing comprises a main bodyhaving an insertion hole at a first main surface thereof for receivingtherethrough the tubular sleeve, and a lid member for covering theinsertion hole, the lid member having the pair elastically deformableengaging portions which project from a second main surface of the mainbody opposite the first main surface when the lid member covers theinsertion hole.
 8. An optical connector adapter according to claim 7;wherein the main body of the adapter housing comprises an integrallymolded structure.
 9. An optical connector adapter according to claim 1;wherein the adapter housing has stacking means for stacking the adapterhousing with at least one other adapter housing of another opticalconnector adapter.
 10. An optical connector adapter according to claim1; wherein the adapter housing has a rotation stopper portion forengagement with an outer periphery of the, ferrule for restrictingrotational movement of the ferrule relative to the adapter housing. 11.An optical connector comprising the optical connector adapter accordingto claim
 1. 12. An optical connector adapter comprising: a main bodyhaving first and second opposite main surfaces; a tubular sleevedisposed in the main body and having opposite open ends each forreceiving a ferrule supporting an optical fiber to bring front end facesof the ferrules into contact with each other to optically connecttogether the optical fibers; and a lid member for detachable connectionto the first main surface of the main body, the lid member having atleast one elastically deformable engaging portion which projects fromthe second main surface of the main body when the lid member isdetachably connected to the first main surface for detachable engagementdirectly to a mounting board or for detachable engagement to a mountingmember detachably engageable with the mounting board to detachably mountthe adapter housing to the mounting board.
 13. An optical connectoradapter according to claim 12; wherein the main body has an insertionhole for receiving therein the sleeve, the lid member having a lidportion for covering the insertion hole when the lid member isdetachably connected to the first main surface of the main body.
 14. Anoptical connector adapter according to claim 13; wherein the adapterhousing has a projection disposed at an outer edge of an opening of theinsertion hole for contacting an outer peripheral surface of the sleeveto prevent removal of the sleeve from the insertion hole.
 15. An opticalconnector adapter according to claim 12; wherein the main body of theadapter housing comprises an integrally molded structure.
 16. An opticalconnector adapter according to claim 12; wherein the at least oneelastically deformable engaging portion comprises a pair of elasticallydeformable engaging portions projecting from the second main surface ofthe main body when the lid member is detachably connected to the firstmain surface for detachable engagement directly to a mounting board orfor detachable engagement to a mounting member detachably engageablewith the mounting board to detachably mount the adapter housing to themounting board.
 17. In combination: an optical connector adaptercomprised of a tubular sleeve having opposite open ends each forreceiving a ferrule supporting an optical fiber to bring front end facesof the ferrules into contact with each other to optically connecttogether the optical fibers, and an adapter housing supporting thereinthe sleeve, the adapter housing comprising a main body having aninsertion hole at a first main surface thereof for receivingtherethrough the tubular sleeve and a lid member for covering theinsertion hole, the lid member having at least one engaging portionwhich projects from a second main surface of the main body opposite thefirst main surface when the lid member covers the insertion hole fordetachable engagement directly to a mounting board or for detachableengagement to a mounting member detachably engageable with the mountingboard to detachably mount the adapter housing to the mounting board; anda jig for disengaging the engaging portion of the lid member from themounting board or from the mounting member to detach the adapter housingfrom the mounting board or from the mounting member detachably engagedwith the mounting board.
 18. A combination according to claim 17;wherein the engaging portion is elastically deformable; and wherein thejig comprises a pin member for insertion between the engaging portionand the main body of the adapter housing to elastically deform theengaging portion for detaching the adapter housing from the mountingboard or from the mounting member detachably engaged with the mountingboard.
 19. A combination according to claim 17; wherein the at least oneengaging portion of the lid member comprises a pair of engaging portionswhich project from a second main surface of the main body opposite thefirst main surface when the lid member covers the insertion hole fordetachable engagement directly to a mounting board or for detachableengagement to a mounting member detachably engageable with the mountingboard to detachably mount the adapter housing to the mounting board. 20.A combination according to claim 19; wherein each of the pair ofengaging portions is elastically deformable; and wherein the jigcomprises a pair of pin member each for insertion between the main bodyand the respective engaging portions to elastically deform the engagingportions for detaching the adapter housing from the mounting board orfrom the mounting member detachably engaged with the mounting board.